Aerothermal optimisation of late suction surface cooling for high-pressure nozzle guide vanes

提高喷气发动机中的涡轮机入口温度可提高循环效率。高压喷嘴导向叶片暴露于高于其熔点的温度。气膜冷却用于降低高压喷嘴导叶的金属温度和增加导叶寿命。由于与冷却剂喷射相关的高损失，通常从吸力面省略薄膜冷却。在文献中，很少有研究量化与后期吸力面气膜冷却相关的质量流、气动损失和金属效率影响。该项目旨在开发新的分析模型、数值工具和实验技术来预测这些影响，并提出最佳的吸力面薄膜冷却设计。将开发一维分析模型来预测气动损失与冷却孔表面距离的函数关系。分析模型也将用于预测与冷却剂注入相关的质量流量变化。将开发传热模型来研究多个冷却孔对金属效率的附加效应。计划对现有的和新的冷却孔几何形状进行三维数值研究。牛津大学的ECAT设施将用于进行高精度温度和质量流量测量。实验数据和分析预测将进行比较。

Increasing the turbine entry temperature in a jet engine increases the cycle efficiency. High-pressure nozzle guide vanes are exposed to temperatures above their melting points. Film cooling is used to reduce the metal temperature of high-pressure nozzle guide vanes and increase vane life. Film cooling is often omitted from the suction surface due to high losses associated with coolant injection. There are few studies in the literature that quantify the mass flow, aerodynamic loss and metal effectiveness effects associated with late suction surface film cooling. This project aims to develop new analytical models, numerical tools and experimental techniques to predict these effects and propose an optimal suction surface film cooling design.One-dimensional analytical models will be developed to predict aerodynamic loss as a function of cooling hole surface distance. Analytical models will also be used to predict mass flow changes associated with coolant injection. Heat transfer models will be developed to study the additive effects of multiple cooling holes on metal effectiveness. Three-dimensional numerical studies are planned on existing and new cooling hole geometries. The ECAT facility at the University of Oxford will be used to conduct high-accuracy temperature and mass flow measurements. Experimental data and analytical predictions will be compared.